[x86] Allow generating user-space headers without a compiler

debian/changelog

@@ -8,6 +8,7 @@ linux (4.19~rc1-1~exp1) UNRELEASED; urgency=medium
   * locking/lockdep: Delete unnecesary #include (fixes liblockdep build)
   * [hppa] debian/control: Simplify build-dependencies for 64-bit toolchain
   * Compile with gcc-8 on all architectures
+  * [x86] Allow generating user-space headers without a compiler
 
  -- Ben Hutchings <ben@decadent.org.uk>  Mon, 27 Aug 2018 14:36:54 +0100
 

debian/patches/bugfix/x86/x86-allow-generating-user-space-headers-without-a-co.patch

@@ -0,0 +1,47 @@
+From: Ben Hutchings <ben@decadent.org.uk>
+Date: Wed, 29 Aug 2018 20:26:46 +0100
+Subject: x86: Allow generating user-space headers without a compiler
+Forwarded: https://lore.kernel.org/lkml/20180829194317.GA4765@decadent.org.uk/T/#u
+
+When bootstrapping an architecture, it's usual to generate the
+kernel's user-space headers (make headers_install) before building a
+compiler.  Move the compiler check (for asm goto support) to the
+archprepare target so that it is only done when building code for the
+target.
+
+Fixes: e501ce957a78 ("x86: Force asm-goto")
+Reported-by: Helmut Grohne <helmutg@debian.org>
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+---
+ arch/x86/Makefile | 11 +++++++----
+ 1 file changed, 7 insertions(+), 4 deletions(-)
+
+diff --git a/arch/x86/Makefile b/arch/x86/Makefile
+index 94859241bc3e..7df47ff45f68 100644
+--- a/arch/x86/Makefile
++++ b/arch/x86/Makefile
+@@ -175,10 +175,6 @@ ifdef CONFIG_FUNCTION_GRAPH_TRACER
+   endif
+ endif
+ 
+-ifndef CC_HAVE_ASM_GOTO
+-  $(error Compiler lacks asm-goto support.)
+-endif
+-
+ #
+ # Jump labels need '-maccumulate-outgoing-args' for gcc < 4.5.2 to prevent a
+ # GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46226).  There's no way
+@@ -312,6 +308,13 @@ PHONY += vdso_install
+ vdso_install:
+ 	$(Q)$(MAKE) $(build)=arch/x86/entry/vdso $@
+ 
++archprepare: checkbin
++checkbin:
++ifndef CC_HAVE_ASM_GOTO
++	@echo Compiler lacks asm-goto support.
++	@exit 1
++endif
++
+ archclean:
+ 	$(Q)rm -rf $(objtree)/arch/i386
+ 	$(Q)rm -rf $(objtree)/arch/x86_64

debian/patches/series

@@ -75,6 +75,7 @@ bugfix/x86/mmap-add-an-exception-to-the-stack-gap-for-hotspot-jvm.patch
 bugfix/powerpc/powerpc-lib-sstep-fix-building-for-powerpcspe.patch
 bugfix/powerpc/powerpc-lib-makefile-don-t-pull-in-quad.o-for-32-bit.patch
 bugfix/arm/arm-mm-export-__sync_icache_dcache-for-xen-privcmd.patch
+bugfix/x86/x86-allow-generating-user-space-headers-without-a-co.patch
 
 # Arch features
 features/mips/MIPS-increase-MAX-PHYSMEM-BITS-on-Loongson-3-only.patch